Relief or intaglio plastic plate and method of manufacture thereof

ABSTRACT

Disclosed is a relief or intaglio plastic plate and the method of manufacture thereof whereby an image-bearing transparency of the indicia the plate is to print is permanently bonded to a base plate and thereafter selected areas of the transparency corresponding to the image together with areas of the base plate underlying the selected areas are removed to desired depths.

O Umted States Patent [151 3,658,532

Gilligan [451 Apr. 25, 1972 54 RELIEF 0R INTAGLIO PLASTIC PLATE 3,271,151 9/1966 Staehle et al ..96/36.3 x AND METHOD OF MANUFACTURE 3,245,793 4/1966 Smith 96/36.3 X THEREOF 3,305,359 2/1967 Delmont. .....96/36.3 X 3,356,501 12/1967 Tongs ..96/36.3 [72] Inventor: Joseph Edward Gilligan, 68 Lindberg Avenue, West Newton, M 02165 FOREIGN PATENTS OR APPLICATIONS [22] Filed: July 1, 1969 757,037 4/1967 Canada ..96/36.3

[21] Appl'No': 838262 Primary E.raminerDavid Klein Attorney-Gerald J. Ferguson, Jr. [52] US. Cl ..96/36.3, 156/l4, 96/36,

96/36.4 [57] ABSTRACT 2 2 3E 7 Disclosed is a relief or intaglio plastic plate and the method of 1 0 156/16 manufacture thereof whereby an image-bearing transparency of the indicia the plate is to print is permanently bonded to a base plate and thereafter selected areas of the transparency [56] References cued corresponding to the image together with areas of the base UNITED STATES PATENTS plate underlying the selected areas are removed to desired de ths. 3,488,191 l/1970 ODonnell ..96/36 p 2,875,051 2/1959 DeMaria ..96/36.3 X 7 Claims, 10 Drawing Figures RELIEF R INTAGLIO PLASTIC PLATE AND METHOD OF MANUFACTURE THEREOF BACKGROUND OF THE INVENTION This invention relates to relief or intaglio plastic plates and more particularly to plates created by the so-called photo-engraving process.

One example of the usefulness of the present invention is found in the manufacture, of identification cards of the type disclosed in US. Pat. No. 3,217,643 wherein one portion of the card is provided with printed matter that identifies the one who issues the card and another portion is provided with an etched printing member adapted to imprint on a sales slip or the like indicia that identifies the one to whom the card was issued.

As disclosed in that patent, the printing member is made by photographically creating an image-bearing transparency of theindicia that identifies the one to whom the card is to be issued. This transparency is then brought into intimate contact with a coating of a light sensitive emulsion carried by a base plate after which light is projected through the transparency and against the emulsion to create thereon a reproduction of said indicia in the form of light affected areas surrounded by light unaffected areas. Thereafter, the transparency is removed and is either discarded or stored for subsequent use; and finally, the light unaffected areas of the emulsion and the underlying areas of the plate are etched to desired depths and thus create a plate adapted to print said indicia.

While printing plates created by this process are satisfactory, the process is open to the objection that speed of producing printing plates is substantially limited in that each base plate with its light sensitive emulsion must be separately exposed. In order to substantially lessen the production time, in accordance with this invention, a thin film which includes a light sensitive emulsion is exposed to the indicia to be reproduced. The thickness of the film is such that it preferably can be stored on the casset of a camera and fed therethrough at a desired rate of speed. Hence, it can be readily seen that successive frames can be rapidly fed past a display tube controlled by a computer which rapidly formats the indicia displayed at the tube whereby each successive exposed frame would contain indicia relating to a particular credit card or the like. Since the thin film is not substantial enough to be used as a credit card or the like, it is subsequently permanently bonded to a base plate whereby the composite possesses the requisite strength for whatever purpose it is to be put to which may be a credit card, printing plate, decorative plate, etc. The composite is then further processed to create either a relief or intaglio plate as will be described in more detail hereinafter.

SUMMARY OF THE INVENTION In practicing the invention in accordance with one embodiment thereof, suitable non-photopolymerizable material is coated on one side with a light sensitive emulsion which is then photographically exposed to a copy of the indicia the plate is to print. Thereafter, the emulsion is processed in a well known manner to create an image-bearing thin film containing said indicia. During the processing of the emulsion, the imagebearing areas of the emulsion become hardened and so form a resist while the remaining areas of the emulsion are washed off the film. The thin film thus formed is then bonded to a base plate of non-photopolymerizable material; and finally, those areas of the thin film and base plate which underlie the washed away areas of the emulsion are etched or washed out to desired depths and so leave printable replicas of the indicia.

In accordance with another embodiment of the invention a photopolymerizable plastic material is coated on one side with a light sensitive emulsion which is then photographically exposed to a copy of the indicia the plate is to print and thereafter processed to create an image-bearing thin film containing the indicia. During the processing of the emulsion, those areas thereof that were affected by light during exposure turn opaque and become hardened while those areas thereof that were not affected by light are washed off the film. After the image-bearing thin film has been thus created, it is bonded to a base plate of photo-polymerizable material and then actinic light is projected down through those areas of the thin film and base plate which underlie the washed away areas of the emulsion as a result of which these areas become polymerized. Thereafter, the opaque areas of the emulsion are removed and the underlying areas of the thin film and base plate are etched or otherwise removed to desired depths and so create a relief printing plate.

Other objects and advantages of this invention will become apparent upon reading the appended claims in conjunction with the following detailed description and the attached drawmg.

BRIEF DESCRIPTION OF THE DRAWING For a more complete description of the invention, reference may be made to the accompanying drawing wherein the various figures show in enlarged cross-sectional views the various steps employed in practicing the invention.

FIG. 1 illustrates a typical member for use with an invention comprising plastic support for a light sensitive emulsion.

FIG. 2 illustrates the member 10 after it has been processed to form an image resist on the plastic support of FIG. 1.

FIG. 3 illustrates the image-bearing thin film of FIG. 2 bonded to a typical base plate.

FIG. 4 is illustrative of one embodiment of the invention wherein the plastic support of FIG. 1 and the base plate of FIG. 3 have been etched by a solvent, the support and base plate being soluble in the same solvent.

FIGS. 5 and 6 illustrate another embodiment of the invention where the plastic support of FIG. 1 and the base plate of FIG. 3 are etched by different solvents.

FIGS. 7 through 10 illustrate a further embodiment of the invention where the plastic support of FIG. 1 and the base plate of FIG. 3 are like photopolymerizable materials, FIGS. 9 and 10 illustrating the formation of a printing plate after exposure to actinic light and appropriate etching.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS OF THE INVENTION As shown in FIG. 1, a plastic member 10 is rendered light sensitive by providing it with a coating of a light sensitive emulsion 11 such as silver halide gelatin. The combined thickness of the member 10 and the emulsion 11 is preferably approximately 1-17 mils, this thickness range corresponding to that of a thin film as employed hereinafter in the specification and claims.

The light sensitive plastic member may be either in sheet or roll form. Preferably, however, it is made in roll form so that it may be stored in the casset (not shown) of a camera and fed there through at a desired rate of speed. When stored in this manner, the light sensitive plastic member can be rapidly fed past a display tube connected to a computer which rapidly for mats the indicia which is displayed at the tube. The roll can be divided into a plurality of frames so that as each frame of the roll passes in front of the tube, a new set of indicia is displayed and thus the light sensitive member can be rapidly exposed preparatory to the etching step to be described hereinafter.

In accordance with one embodiment of the invention, the plastic member 10 is preferably made from a vinyl compound such as polyvinyl chloride but it may be made from polystyrene, cellulose acetate, cellulose acetate butyrate, ethyl cellulose or an acrylic resin, etc., all of which are soluble in solvents such as methyl ethyl ketone, ethyl acetate, etc. The term solvent is used in its broadest sense to describe a solution which renders the materials herein mentioned in such condition that when they are pressed against a material of similar plastic formulation, they are readily laminated.

As the light sensitive plastic member travels through the camera, the emulsion 11 is photographically exposed to a copy of the indicia the plate is to print and then developed to create a positive image-bearing thin film 12. As the emulsion is being so processed, the image areas 13 become hardened and so form a resist but the surrounding areas 14 are washed away (FIG. 2).

After the positive image-bearing thin film 12 has been thus formed, it is permanently bonded to a base plate 15 (FIG. 3) to produce a structure ready to be etched and so create a printing plate. The thickness of the base plate is largely dependent upon the particular application in which the plate is employed. The term etched is also used in its broadest sense to describe the removal of the materials herein mentioned when brushed, sprayed or otherwise treated with a solvent.

The base plate 15 is preferably made from a vinyl compound such as polyvinyl chloride but it too may also be made from polystyrene, cellulose acetate, cellulose acetate butyrate, ethyl cellulose or an acrylic resin, etc., since all are soluble in solvents such as methyl ethyl ketone, ethyl acetate, etc. The bonding of the thin film to the base plate may be effected by applying a thin layer of the methyl ethyl ketone between the two and then applying pressure therebetween or the bonding may be effected by heat pressing the thin film and the base plate together.

After the structure has been assembled, the top surface thereof is brushed, sprayed or otherwise treated with a solvent such as methyl ethyl ketone or ethyl acetate to etch or wash down through those areas of the plastic member which underlie the washed away areas 14 of the emulsion and into the base plate to a desired depth and so create in relief reproductions of the indicia (FIG. 4).

While in this embodiment of the invention, the thin film and base plate are made from materials that are soluble in the same solvents, additional advantages are to be gained when they are made from materials that are soluble in different solvents. For example; when the thin film and the plate do so differ, the thin film acts as a resist while the plate is being etched with the result that a deeper etch may be obtained without danger of the under-cutting which takes place during an etching operation adversely affecting the printing surfaces of the plate. In addition, if the thin film and plate differ in color, a contrast in color may be obtained between the faces of the printing surfaces and the etched out areas of the plate and this, of course, is important especially when the indicia includes the personal signature of the one to whom the card is issued since it enables one to more readily read the signature.

In accordance with another embodiment of the invention, plastic member 10 and base plate 15 are made from materials that are soluble in different solvents. For example, the member 10 may be made from a plastic material such as polyvinyl alcohol (PVA) which is soluble in hot or cold water depending on the type of PVA as is well known in the art while the base plate 15 may be made from a metal such as copper, zinc, magnesium or the like or from a compound such as polyvinyl chloride, polystyrene, cellulose acetate, cellulose acetate butyrate, ethyl cellulose, acetate butyrate, ethyl cellulose or an acrylic resin. As in the previous embodiment of the invention, the member 10 is coated with a light sensitive emulsion 11 (FIG. I) such as silver halide gelatin, which is exposed to a copy of the indicia the plate is to print and then processed to create a positive image-bearing thin film 12. As explained, heretofore, during the processing operation, the image areas 13 of the emulsion become hardened while the remaining areas 14 of the emulsion are washed off the film (FIG. 2).

After the thin film has been thus made, it is permanently bonded by appropriate techniques to a base plate 15 (FIG. 3) and then those areas of the thin film 12 underlying the washed away areas 14 of the emulsion are removed by subjecting them to the action of a solvent such as water of appropriate temperature (FIG. 5). 1n the event the base plate 15 is made from metal such as copper, those areas thereof underlying the removed areas of the film are etched to desired depths by subjecting them to the action of a solvent such as ferric chloride (FIG. 6). In the event, however, that the base plate 15 is made from polystyrene, cellulose acetate, cellulose acetate butyrate, ethyl cellulose, or an acrylic resin, a solvent such as methyl ethyl ketone or ethyl acetate is used to etch to desired depths those areas of the base plate underlying the removed areas of the film.

In accordance with still another embodiment of the invention, the thin film 10 is made from a photopolymerizable material of the type disclosed by L. Plambeck and others in U.S. Pats. among which may be mentioned U.S. Pat. Nos. 2,760,863 and 2,791,504.

As in the previous embodiments of the invention, the film 10 is provided with a coating of a light sensitive emulsion 11 (FIG. 1) which is exposed to a copy of the subject matter the plate is to print, then processed to create a negative imagebearing thin film 16 (FIG. 7) which is then permanently bonded to a base plate 17 oflike photopolymerizable material (FIG. 8). During the processing of the emulsion, the light unaffected areas 18 thereof which are the reproductions of the indicia are washed off the film 10 while the remaining areas 19 become hardened and turn opaque. After the thin film has been bonded to the base plate, actinic light (FIG. 9) is projected through the bared areas of the plastic member 10 and the underlying areas of the base plate 17 with the result that these areas 20 become polymerized. Thereafter, the hardened areas 19 of the film are removed by treating them with a solvent such as isopropyl alcohol; and finally, the unpolymerized areas of the film and base plate thus bared are etched or washed out to desired depths by treating them with a solvent such as a solution of sodium hydroxide (FIG. 10).

A further modification of the invention involves the utilization ofa metal such as zinc, copper, magnesium, etc. for use as the member 10 and the utilization of a plastic material such as PVA, polyvinyl chloride, polystyrene, cellulose acetate, cellulose acetate butyrate, ethyl cellulose or an acrylic resin for use as the base plate 15. Once again, of course, a light sensitive emulsion would be provided on the surface of the metal member 10. The necessary steps for manufacturing a printing plate would correspond to those already discussed hereinbefore with respect to FIGS. l-3 and 5-6, typical solvents for the above materials having already stated.

Regardless of the particular material selected for the member 10, in some applications it may be desirable to incorporate therein either magnetic or electrically conducting material so that a printing plate may be produced, the final characteristics of which would be such as described in U.S. Pat.No. 3,111,495.

Certain modifications of applicants invention are obvious to those of ordinary skill in this art. For example, it may be desirable in some applications to permanently bond the thin film to the base plate 15 prior to exposing the light sensitive emulsion. Of course, this would make it more difficult to store the thin film on a cassette with its attendant high speed processing advantages.

Further, depending on whether a relief or intaglio plate is desired, it will be obvious that the image borne by the image bearing thin film may be either positive or negative depending on the particular method chosen to manufacture the plate, illustrative embodiments of such methods having been described hereinbefore with respect to FIGS. l-10. Also, the depth of the etch may be such as to extend through the base plate such that holes are formed in the composite, which holes may be used for data processing purposes, for example.

Further, although the preferred embodiment of this inven tion has been described in relation to a printing plate, it is to be understood that other types of relief or intaglio plastic plates may be produced in accordance with the teachings of this invention. Thus, decorative plates for use with lamp shades, Christmas cards, wall plaques, emblems, etc. may be produced in accordance with the teachings of this invention. From the foregoing it is to be understood that the term plastic plate extends where either the thin film 12 is plastic or the base plate 15 is plastic or both are plastic.

Inasmuch as many widely different embodiments of this invention can be made without departing from the spirit and scope thereof, it is to be understood that the invention is not limited except as defined by the claims.

I claim:

1. The process of making a plastic plate which comprises forming a resist over selected portions of a plastic member to form an image-bearing thin film, permanently bonding said thin film to a base plate with the resist portions on the unbonded surface of said thin film, and thereafter removing (1) selected areas of said thin film and (2) the areas of the base plate underlying said selected areas to desired depths.

2. The process as in claim 1 where said resist is photographically formed.

3. The process of making a plastic plate which comprises forming a resist over selected portions of a plastic member to form an image-bearing thin film, permanently bonding said thin film to a base plate with the resist portions on the unbonded surface of said thin film, said base plate being com prised of material soluble in the same solvents in which said thin film is soluble, and thereafter etching down through (1) selected areas of said thin film corresponding to the non-resist portions of said thin film and (2) the areas of the base plate underlying said selected areas to desired depths.

4. The process of making a plastic plate which comprises forming a resist over selected portions of a plastic member to form an image-bearing thin film, permanently bonding said thin film to a base plate with the resist portions on the unbonded surface of said thin film, said base plate being comprised of material insoluble in a solvent in which said thin film is soluble, treating said thin film with a solvent in which said thin film is soluble to etch down to said base plate through selected areas of said thin film corresponding to the non-resist portions of said thin film, and then treating the areas of the base plate underlying the selected areas of said thin film with a solvent in which the base plate is soluble to etch down there through to desired depths.

5. The process of making a plastic plate which comprises forming a resist over selected portions of a polyvinyl chloride member to form an image-bearing thin film, permanently bonding said thin film to a base plate with the resist portions on the unbonded surface of said thin film, said base plate being comprised of polyvinyl chloride, treating said thin film and said plate with a solvent in which said polyvinyl chloride is soluble to etch down through (1) selected areas of said thin film corresponding to the non-resist portions of said thin film and (2) the areas of the base plate underlying said selected areas to desired depths.

6. The process of making a plastic plate which comprises forming a resist over selected portions of a photopolymerizable member permanently bonding said thin film to a base plate with the resist portions on the unbonded surface of said thin film, said base plate being comprised of photopolymerizable material, projecting light down through selected areas of said thin film corresponding to the non-resist portions of said thin film to polymerize (1) those areas of the thin film and (2) the areas of the base plate underlying said selected areas, and then etching down through the remaining areas of said thin film and the underlying non-polymerized areas of said base plate to desired depths.

7. The process of making a plastic plate which comprises forming a resist over selected portions of a plastic member to form an image-bearing thin film, permanently bonding said thin film to a base plate with the resist portions on the unbonded surface of said thin film, and thereafter removing (1) selected areas of said thin film corresponding to the non-resist portions of said thin film and (2) the areas of the base plate underlying said selected areas to desired depths. 

2. The process as in claim 1 where said resist is photographically formed.
 3. The process of making a plastic plate which comprises forming a resist over selected portions of a plastic member to form an image-bearing thin film, permanently bonding said thin film to a base plate with the resist portions on the unbonded surface of said thin film, said base plate being comprised of material soluble in the same solvents in which said thin film is soluble, and thereafter etching down through (1) selected areas of said thin film corresponding to the non-resist portions of said thin film and (2) the areas of the base plate underlying said selected areas to desired depths.
 4. The process of making a plastic plate which comprises forming a resist over selected portions of a plastic member to form an image-bearing thin film, permanently bonding said thin film to a base plate with the resist portions on the unbonded surface of said thin film, said base plate being comprised of material insoluble in a solvent in which said thin film is soluble, treating said thin film with a solvent in which said thin film is soluble to etch down to said base plate through selected areas of said thin film corresponding to the non-resist portions of said thin film, and then treating the areas of the base plate underlying the selected areas of said thin film with a solvent in which the base plate is soluble to etch down there through to desired depths.
 5. The process of making a plastic plate which comprises forming a resist over selected portions of a polyvinyl chloride member to form an image-bearing thin film, permanently bonding said thin film to a base plate with the resist portions on the unBonded surface of said thin film, said base plate being comprised of polyvinyl chloride, treating said thin film and said plate with a solvent in which said polyvinyl chloride is soluble to etch down through (1) selected areas of said thin film corresponding to the non-resist portions of said thin film and (2) the areas of the base plate underlying said selected areas to desired depths.
 6. The process of making a plastic plate which comprises forming a resist over selected portions of a photopolymerizable member permanently bonding said thin film to a base plate with the resist portions on the unbonded surface of said thin film, said base plate being comprised of photopolymerizable material, projecting light down through selected areas of said thin film corresponding to the non-resist portions of said thin film to polymerize (1) those areas of the thin film and (2) the areas of the base plate underlying said selected areas, and then etching down through the remaining areas of said thin film and the underlying non-polymerized areas of said base plate to desired depths.
 7. The process of making a plastic plate which comprises forming a resist over selected portions of a plastic member to form an image-bearing thin film, permanently bonding said thin film to a base plate with the resist portions on the unbonded surface of said thin film, and thereafter removing (1) selected areas of said thin film corresponding to the non-resist portions of said thin film and (2) the areas of the base plate underlying said selected areas to desired depths. 